CVE-2025-59980 is an authentication bypass vulnerability identified in the FTP server of Juniper Networks Junos OS, classified under CWE-305 (Authentication Bypass by Primary Weakness). The flaw arises when the FTP server is enabled and a user named 'ftp' or 'anonymous' is configured; these users can authenticate without providing the configured password. This allows an unauthenticated, remote attacker to gain limited read-write access to the home directory of these accounts on the device. The vulnerability affects all Junos OS versions prior to 22.4R3-S8, 23.2 versions before 23.2R2-S3, and 23.4 versions before 23.4R2, indicating a broad range of affected releases. Exploitation requires no privileges or user interaction and can be performed remotely over the network, increasing the attack surface. The impact is limited to confidentiality and integrity of files accessible via the FTP server, with no direct availability impact. Although no known exploits have been reported in the wild, the vulnerability could be leveraged to access sensitive configuration files or plant malicious files, potentially facilitating further compromise or disruption of network operations. Junos OS is widely deployed in enterprise and service provider environments, making this vulnerability relevant to organizations relying on Juniper network devices. The absence of patches in the provided data suggests immediate upgrading to the fixed versions is critical once available. Network administrators should also consider disabling FTP services or restricting access to trusted hosts to mitigate exposure.

For European organizations, this vulnerability poses a moderate risk primarily to network infrastructure devices running Junos OS with FTP enabled and configured with 'ftp' or 'anonymous' users. Unauthorized read-write access could lead to exposure or alteration of critical configuration files, potentially undermining device integrity and network security. This could facilitate lateral movement, data exfiltration, or persistent access by attackers. Given Juniper's significant market presence in European telecom operators, ISPs, and large enterprises, exploitation could disrupt critical communications infrastructure or sensitive data flows. The vulnerability does not directly impact availability but compromises confidentiality and integrity, which can have cascading effects on network reliability and trustworthiness. Organizations in sectors such as telecommunications, finance, government, and critical infrastructure are particularly at risk due to their reliance on secure network operations. The medium severity rating reflects the balance between ease of exploitation and limited scope of access, but the potential for misuse in targeted attacks remains significant.

1. Upgrade affected Junos OS devices to the fixed versions: 22.4R3-S8 or later, 23.2R2-S3 or later, and 23.4R2 or later as soon as patches are available. 2. Temporarily disable the FTP server on Junos OS devices if it is not essential for operations to eliminate the attack vector. 3. If FTP must be used, avoid configuring 'ftp' or 'anonymous' users, or restrict their permissions and access strictly. 4. Implement network-level access controls such as firewall rules or ACLs to limit FTP server access to trusted management networks or IP addresses. 5. Monitor FTP server logs and network traffic for unusual login attempts or file access patterns indicative of exploitation attempts. 6. Employ intrusion detection/prevention systems (IDS/IPS) with signatures or heuristics to detect anomalous FTP activity. 7. Conduct regular audits of device configurations and user accounts to ensure compliance with security best practices. 8. Educate network operations teams about this vulnerability and the importance of minimizing FTP exposure on critical devices.